Friction band-brake



F. E. WILLIAMS.

FRICTION BAND BRAKE.-

APPLICATION FILED MAR. 6, I917.

Flg l w/mssm- INVENTOR ATTORNEY 1,353,370, v PatentedSpt 2L1920'.

I that the constant N T T E Y AHNT s !CE;v

v .bFRANK n. wa -Am s AL AMBRA, oAL'InonnIaQ T o allwhom it may concern:

Be it known that I, FRANK'E. :WILLIAMS, a citizen of the UnitedStates, residing in the city-of Alhambra, county of Los Angeles, State of California, have invented new and useful Improvements in Friction Band-Brakes, of which the following is a V specification.

, My invention relates to a: combination frictio'nb'and brake gear designed to be .constant in action by which a weight .or'load may be suspended in any desired position, and raised 'or lowered at will; so constructed brake resistance may be easily overcome by properly applied traction, and the brake automatically hold the weight or load again in a Jfi-xed position as soonas traction ceases. A The objects of my invention are to provide a means-bywhich a weight, as a geographical globe in a school room, maybe suspended in Jan out-of-the-way position;

' drawn down to anyedesired level for demonsurround pulley 3; and

which is attractive in appearance,

stration purposes, and replaced in out-ofthe-way position, and to do this by a device simple, effective and cheap.

I attain these objectszby. the mechanismillustrated in the accompanying drawings, in which-'- V Figure 1 is a front elevation of the complete invention attached in a fixed position overhead. 7

Fig. 2 is a cross section on in in the direction of the arrow in 7 Fig. 3 shows a cross-section of a modification of my invention.

Fig. 4 shows a view of said modification in the direction of'the arrow in Fig.

like scale, loolr- Referring particularly to the drawings X, represents a ceiling joist or other fixed 3 brake gear, and comprises a shaft 2 with pulley 3 attached thereto suspended in ordinary brackets 2* and 2 by means of bearing tips 15; the pulley '3 is provided with flanges 3*, between which passes brake ban d P and traction belt- 5; a brake band holder 1, attached to X and formed to partially a traction belt 5.

In Fig. 1 the brake band holder 1 is cut out, exposing brake band 4 withinflanges 3* of pulley 3; also showing traction belt 5 lying between brake band 4 and pulley 8.

rn'iorion BAND-BRAKE.

'tion is normally overcome Fig. 1.

friction between Specification of Letters Batent. 1 3,1 (3 1 61"S t; 19 20 Application fil ed March 6, 1917. Serial No.-152,835

' I Brake band 4? comprises threeparts for the purposes of-this invention, viz. (1) a resilient medium 6,. as a .coil'spring, one ex-' band 4, preferably of leather;'a nd (3) I i adjustable terminal 7 as a threaded bar, one end vof.which is attached to flexible band 4, and the otherend adapted to pass through a hole in the distal end of holder 1, and provided with a suitable nut to operate thereon.

;.:Holder 1 is provided with parallel rods 14, between the ends thereof for thesake of rigidityysaid rods also serving asguides to preventtraction belt 5' riding'fianges 3;

Under normal operating conditions the weight. or load I) exerts traction through flexible connection D This tracby constant brake friction between band 4*" and pulley .3, and

ofrod'? provides a safety margin of-friction over and above-that "necessary toovercome said traction by load D.

on shaft :2

- adjustment. oftensioni of band Pby' means To revolve shaft 2 traction is made I endless'belt 5' in either direction and when said traction is sufl'icient'to overcome the normal brake friction and safety margin, then pulley and shaft revolve .on bearings 15 andweight D is raised or lowered correspondingly;

Be it understood that variation in load '1) may be compensated for byvariation in tension of brake band 4: through operation of adjustable terminal 7. That is, thegreater the tension on brake band 4? the greater the friction on pulley 3 to off-set increase in load v D and vice versa;

Beit further borne in mind that although traction belt 5 lies between band 4"? and pulley 3, the frictional relation between said band 4 and pulley ,fected thereby.

3 is not appreciably afs It will be observed that traction on, belt 5' in one direction w1ll operate to increase the between belt fianclband ;4 and to the re, siliency in terminal. 6), thus in an appreciable degree lessening the tension of band. 4

length of brake bandied (duev to thefriction At the same time the 7 the oplower the same. Y

posite direction has no equivalent lessening of tension of brake band 4%, because of the rigidity of its attachment through terminal belt 5 is necessary to revolve pulley 3 in one direction than'in the other. For obvious reasons, therefore, thexload D is suspended to exert traction on pulley 3 in the direction :of -:greatest difficulty zto operate the same. In other words,:the brake ilOfLdeOI' inertia existing when brake is in :operation and load is suspended, is arranged 5170 be more easily overcome by traction on belt 5 in a direction to lift load D than '-'to It also appears that by simple modifieation ofithe brake bandholder f1 to'more or less surround :pulley 3, the frictional surface ofbandl -on pulley 3'may be'inereased or-decreased. g V

.In the modification (Figs. 3 and :4) the holder 1, in conjunction with band 4* entirely encircles (pulley 3. Traction belt "5,

after leaving pulley 3 "on .eitherz side thereof, passes through slots .11, 311 provided in holder 1. In this constructionholder :1, at its junction withonea-extremity ojf band-4*, is attached by any-simple' mechanical means to bracket 2 as at 9, this 'attachme'nt serving to prevent holder 1 I and band 4- from trevolving with pulley 3. Threaded bar Y7 and nut operating thereon serves to "increase :or

' diminish tension of :band 4%, "as in :previous ably'of-springrmetal, is' formed on described :constr uction, Holder ,1, preferradius than 'is pulley :thus providing in It appears therefore, that less tractionjon a larger itself the resiliency necessary, and so serving in lieu of coil spring 6. a

This IIIOdlfiCELtlOIl "is "applicable to ordinary window shade brackets and may serve asa window shade adjuster, the shade in its proper hanger being the equivalent 1 of load D. I a

,EHaving described my invention I claim of the United Statesuponas new and desire to obtain Letters Patent In a constant friction band brake a I combination of a revolving drum and brake o pulley :attached thereto, vall properly ijourcircling said r'brake pulley; caifiexible brake "band bearing on :said Lpulleymnd permanentlyattached to said holder atoneendf'b means (if an interposed-coil spring, *SflldQOll spring being placed :on itheside ofsaid pula ley correspondingrtoithe'aside' aolf'tsaid drum where suspended load wouldzten'dito unwind the same, the other end :of "said i'brake tband bein :attached to said holder zby means of an :interposed -threaded shaft which passes through a perforation in said holder 7 and provided with. a winged nutat the extremity thereof to operate thereon; :and aflat traction belt riding said 'pulley ibetween said fiexible-brakerband and: said spulley, all sub- F. D. J ONES, OLIVER S. rBA'RNnM 50 naled; :aaband brake holder partially en- I 

